1. Field of the Invention
The present invention relates to methods and apparatus for chemical analysis and more particularly to the analysis, detection, or identification of gases or gasified agents or, analytes based on their adsorption by other materials.
2. Brief Description of Prior Developments
The prior art discloses various methods and apparatus for analyzing gases or gasified agents or analytes based on their adsorption by different types of polymers.
In one such type of apparatus, an array of separate surface acoustic wave (SAW) devices, each coated with a polymer primarily sensitive to one analyte, is used to detect agents. The adsorption of agents causes a frequency shift dependent upon the polymer.
A disadvantage of this type of apparatus results from the use of separate arrays. Arrays are prone to drift owing to temperature or other environmental factors so that each array must be calibrated in a manner to be determined.
A need, therefore, exists for a method and apparatus which avoids these disadvantages.